1. Field of the Invention
The present invention relates to printing systems which print on two sides of a card and further magnetically encode a magnetic medium extending along one side.
2. Description of the Prior Art
FIGS. 1A and 1B respectively illustrate a top side and a bottom side of a conventional prior art plastic card of the non-embossed type to which the present invention relates. The top side includes printing which is thermally fused using a resin or dye-sublimation (D2T2) material coated on a plastic foil carrier which is transferred to a card upon the heating of individual heating elements within the print head which individually print pixels to produce a high quality print of, for example, 300 pixels per inch or more. The smart card IC illustrated in phantom in FIG. 1A is utilized in many applications, such as Subscriber Identity Module (SIM) card which provides user identity in mobile telephony applications, and in other applications requiring onboard stored data. FIG. 1B shows the bottom side of the card including printing and a magnetic stripe upon which a bit track which may be encoded under International Standards Organization (ISO) specifications for credit and other types of cards.
The prior art printing systems, which perform double sided printing of plastic cards, including magnetic stripes such as illustrated in FIGS. 1A and 1B, use three approaches. Each of these approaches results in additional stations (when compared to the present invention) along a transport path of the printing system which contributes complexity, cost and the overall length of the system. It is desirable for printing systems for cards of the type to which the present invention relates to be as small as practically possible so as to minimize the work area which must be allocated to card processing.
The first approach is to provide a mechanism for rotating the cards located between two print stations which is hereinafter referred to as “flipping”. A card which has been previously magnetically encoded to include magnetic data on the magnetic stripe at a magnetic encoding station is transported along a card transport to a first printing station where the top side is printed. Thereafter, the card is transported along the card transport to a card flipper located between the printing stations which flips the card so that the bottom side is now facing upward so that, when the card is moved to the second printing station, the bottom side is printed. This approach suffers from the disadvantage that the card flipper adds to the length of the card transport (about 4 inches in commercial products) since a separate flipper is required to be located between the first and second printing stations which further, in view of the additional length of the transport mechanism, also adds cost to the machine. Also, two printers with their foil feeding mechanisms add cost and complexity.
The second approach is to provide a separate flipper located either before or after a common print station. FIG. 2 illustrates a block diagram of the second approach in which the card flipper 22 is located before the common printing station 24. In FIG. 2, cards are supplied (picked) from a card input 12 and transported to a smart card encoding station 14 by a card transport 18. At the smart card encoding station 14, the aforementioned smart card IC, illustrated in FIG. 1A, is programmed with data provided by a conventional smart card encoder. If the smart card is not verifiably encoded correctly with the data, the card is treated as a rejected card which will not be permitted to be discharged (stacked) into the card output 16. If smart card encoding occurs without error at the smart card encoding station 14, the card is transported along the card transport 18 to a conventional magnetic stripe encoding station 20 at which the data in the form of magnetically recorded bits is encoded onto the magnetic stripe as illustrated in FIG. 1B which may be in accordance with applicable ISO standards. Thereafter, if the magnetic encoding is verified to be without error, the card will be transported ultimately by the card transport 18 to card flipper 22, to printing station 24 and then to the card output 16. The card is transported from the magnetic stripe encoding station 20 to the card flipper 22 which performs the process of rotation of the cards held therein such that the side of the card which is to be printed first at the printing station 24 (typically the side opposite the magnetic stripe) is oriented with the face on which the printing is to occur facing toward the thermally activated heating elements of the printing station 24. When the first side of the card is being printed, which is typically the face of the card illustrated in FIG. 1A, the card flipper 22 is not activated since the correct side of the card on which printing is first to occur is oriented in the right direction relative to the printing head of the printing station 24. The card moves from the card flipper into the printing station 24 where the thermally activated printer of the printing station is activated to print a pattern of pixels produced by selectively heating a linear array of individual heating elements which extend across the width of the card to print the pixels to produce the desired image on the first side to be printed. After the first side of the card is printed, the card is transported back to the card flipper 22, as indicated by the double headed arrow 26, at which the card is flipped 180° so that the side on which no printing has occurred, is now oriented to face the thermally activated linear array of heating elements of the printing station 24. Thereafter, the card is transported back to the printing station 24 for printing the second side and subsequently discharged into the card output 16. Rejected cards resultant from erroneous smart card encoding or magnetic stripe encoding are not output into the card output 16 as the result of a card reject mechanism.
The last approach uses separate printing stations facing the front and rear surfaces of the card to print the two sides. This approach eliminates the need for a card flipper but adds to cost by requiring two printers, including the required foil feeding mechanisms. The length of the card transport is not lessened in view of the addition of another printer which takes up substantially the same space as the flipper which has been eliminated.
U.S. Pat. Nos. 5,709,484 and 5,962,832 disclose apparatus for printing on double sided cards in which a flipper is provided which may also be used to encode an integrated circuit microchip.